Generally, electronic apparatuses such as MP3 players, subscriber identity module (SIM) card readers and the like have user operation interfaces for users to control for example volume or function selection of the electronic apparatuses. These electronic apparatuses are usually controlled in response to switching signals. The user operation interfaces of the touch switches, for example touch pads, knobs and the like, are usually mounted on the electronic apparatuses. In other words, by controlling these user operation interfaces, the touch switches will be triggered to generate switching signals.
Conventionally, the switch operation interface is a disc-shaped touch pad having several (for example four) touch points. Each touch point correlates to a switch. In response to a depressing operation, the corresponding switch is triggered to generate a switching signal. This approach, however, has some drawbacks. For example, the touch pad occupies much area. In addition, some users may have problem in operating the touch pad to control the electronic apparatus.
Another switch operation interface having rotary means is convenient for other users. Such a switch operation interface has a rotatable control rod rotated to trigger the switch. The conventional rotary means for triggering the switch, however, can only provide three-directional switch control actions, i.e. levorotary, dextrorotary and pushing control actions. The number of the switch control actions for a user to perform is limited.